You can get a QS type Cesar salad at Catalina Eddie's. It comes with or w/o chicken.
A simple burger with lettuce and tomato slice at Rosie's.
Fruit at Anaheim Produce.
A decent for the price salmon or roasted chicken meal with salad at ABC Commissary.
In addition to what others have said, I would recommend Backlot Express. They have Southwest Salad with grilled chicken, a grilled chicken club sandwich (which can be healthy-ish) and you can choose carrot sticks instead of fries, or they have a caprese sandwich which also means you can have carrots on the side.
I will say that after Peco's Bills in MK the Backlot Express SW Salad was a big let down, I was doing pretty good watching what I ate but after lunch I was still hungry. I was very underwhelmed by the food at DHS, I'm hoping it improves a lot by the time I go back in 2020.